* CFTC proposes energy trader position limits
* U.S. retail sales down, jobless claims up (Recasts, updates late trading in light of CFTC reaction in paragraph 2)
By Edward McAllister
NEW YORK, Jan 14 (Reuters) - Oil prices fell marginally on Thursday, as weak U.S. economic data and high inventories spurred fears of a sluggish rebound in demand in the world's largest energy consumer.
In late trading, prices briefly edged up as some traders said U.S. regulatory proposals on position limits were not as strict as they had feared. But the gains evaporated and oil closed lower.
U.S. crude for February delivery <CLc1> fell 26 cents to settle at $79.39 a barrel in volatile trade as February crude options expired. An option gives an investor the right but not the obligation to buy or sell crude at a fixed price, which can add to volatility ahead of option expiration.
In London, Brent crude for February <LC0c1>, which expired on Thursday, fell 49 cents to settle at $77.82 a barrel.
"Crude futures are down in follow-through selling after yesterday's EIA data showed very large builds in petroleum inventories. Data on retail sales have been disappointing also," said Brad Samples, analyst at Summit Energy, Louisville, Kentucky
U.S. retail sales fell 0.3 percent last month, the first decline in three months, according to the Commerce Department, while Labor Department data showed more people sought jobless benefits last week. [
]The Commodity Futures Trading Commission moved to limit the role of big traders in energy markets, unveiling proposals to put a hard cap on the size of positions that dealers can hold, but offering a limited exemption for big financial hedgers. [
]The long-awaited proposals will apply to the four most-traded energy contracts on the two major exchanges.
It remains to be seen if the limits -- which CFTC said would affect only the 10 biggest position holders if implemented immediately -- are sufficient to satisfy Congress members who have clamored for regulatory action since oil prices surged to a record $147 in 2008.
Crude prices briefly rose into the positive after the release.
"The energy markets are breathing a sigh of relief that the CFTC proposals on position limits do not seem as bad as feared," said Phil Flynn, analyst at PFGBest Research in Chicago.
"It looks like the CFTC has backed off from its tough talk earlier and now appears to have a lot of room to grant exemptions."
U.S. crude oil stocks rose by a larger-than-expected 3.7 million barrels last week, Energy Information Administration data showed on Wednesday. And while heating oil stocks fell by 1.1 million barrels, stocks for the broader category known as distillates still rose by 1.4 million barrels. [
]U.S. economic activity is now at a low level but is showing signs of modest improvement, the Federal Reserve said on Wednesday in remarks seen as reinforcing the prevailing view that oil demand will grow in 2010. [
]Early this month, oil prices rallied to 15-month highs near $84 a barrel as freezing weather across much of the Northern Hemisphere boosted heating demand. Prices then fell, partly on a surprise jump in U.S. distillate stocks, including heating oil, and a rise in crude oil inventories. (Additional reporting by Gene Ramos and Robert Gibbons in New York, Emma Farge in London, and Alejandro Barbajosa in Singapore; Editing by David Gregorio)